Compound steam-engine.



H. H. PILOHER.

COMPOUND STEAM ENGINE.

Patented June 21, 1910.

APPLICATION FILED 0GT.11, 1906.

2 SHEETS-SHEET 1.

H. H. PILCHER.

COMPOUND STEAM ENGINE.

APPLIOATION FILED 0GT.11, 1900.

Patented June 21, 1910.

2 SHEETS-SHEET 2.

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UNITE HERBERT H. PILCHER, OF MULLINS, TENNESSEE.

COMPOUND STEAM-ENGINE.

Application filed October 11, 1906.

To all whom it may concern:

Be it known that I, HERBERT H. PILCHER, a citizen of the United States, residing at Mullins, in the county of Shelby and State of Tennessee, have invented a new and useful Improvement in Compound Steam-Engines, of which the following is a specification.

This invention relates to a compound high and low pressure steam engine and the object of the invention is an engine of this type which will have a 10W initial cost, which will be economical in the use of fuel, be easily maintained in repair and which will be eificient in operation. In many engines of this type the object of compounding is defeated for the reason that no special care is taken to separate the low pressure from the high pressure steam, and by means of radiation and condensation, the high pressure steam is robbed of considerable heat, especially where there is direct co1nmunication between the high and low pressure cylinders. To operate with proper economy it is necessary that the high temperature steam employed must be utilized in a portion of the engine entirely separated from that where the steam is extended and reduced in temperature and pressure, otherwise the advantages which might be gained by the double expansion are lost since it is the heat carried by the steam and not the steam itself which is the real motive force, the vapor of water being only a vehicle for transporting the heat from the furnace to the engine by the engine transformed into mechanical work. When the high pressure steam is permitted to come into contact with walls cooled by the contact with the low pressure steam, or where a common valve is employed for controlling admission of steam to the two cylinders, the cooler and lower pressure steam absorbs more or less heat from the high pressure steam, and thereby reduces the efiiciency of the engine and results in a considerable waste of fuel.

My invention consists of the novel features of construction hereinafter described, pointed out in the claim and shown in the accompanying drawings, in which- Figure1 is a longitudinal vertical section through my engine; Fig. 2 is an enlarged section taken longitudinally through the high pressure end of the engine; Fig. 3 is a transverse section through the valve casings Specification of Letters Patent.

Patented June 21, 1910.

Serial n0. 338,474.

and through the high pressure cylinder; Fig. l is a detail perspective View of a steam valve; Fig. 5 is a perspective view of an ex-- haust valve.

In these drawings, A represents the high pressure cylinder, which, at its idle end is provided with a compression head A. At its opposite end it is provided with a concavo-convex wall A which separates the high pressure cylinder A from the low pressure cylinder B. These cylinders are supported by a suitable base C upon which is also mounted a casing C in which is journaled a shaft C upon which is fixed a disk D, said disk being within the casing C. A crank rod D is pivotally connected to a combined piston and cross head E, which works in the low pressure cylinder B. A piston F works in the high pressure cylinder and is provided with a piston rod F which works through the partition A and is connected to the piston E. An excess pressure valve F is carried by the piston F in order to prevent too great a pressure in the pressure head A. Steam is admitted through a pipe G into a valve casing H, from which leads a port H into the working end of the cylinder A. The port H is controlled by a rotary valve H provided with a stem H Upon the opposite side of the cylinder A is a valve chamber J which communicates with a cylinder A through a port J, with the cylinder B through a port J 2 and which also communicates at one end with an exhaust pipe L shown in Fig. 3. In the chamber J is a semi-cylindrical hollow valve J 3 also rotatable, said valve opening at one end into the exhaust pipe L and through a slot J formed in the side of the valve, which slot is adapted to register as the valve rotates with the passage J One side of the valve is pressed inwardly thus forming a longitudinal groove or depression running the entire length of the valve, so as to permit steam to pass from the port J through the valve chamber J directly into the port J 2 andthrough the same into the cylinder B. This valve is provided with a stem J 5 and both the valve stems H and J 5 are provided with suitable valve actuating arms K, which are operated by any suitable mechanism and also any suitable form of governor may be employed to control the rotation of these valves. A relief valve M is mounted upon the casing C, as shown in Fig. 1.

The operation of the engine is as follows: Steam is admitted to the high ressure cylinder A to the port H and a ter the high pressure piston F has been driven to the end of its stroke, the valve J 3 opens and allows the steam to enter the low pressure cylinder where it acts upon the larger area of the piston E, and upon the return stroke of the piston E the exhausted steam is admitted through the opening J 4 into the valve J 3 and escapes either into a condenser or to the outer air through the exhaust pipe L. The relief valve F prevents the forming of any compression in the inclosed crank chamber formed by the casing C. The compression head A forms a chamber which conserves heat and pressure limited to the amount of pressure against the working side of the high pressure piston, the valve F opening whenever the pressure in the idle end of the cylinder A exhausts the pressure on the working side and permits a surplus compression to escape to the working side while the compression remaining assists in making the low pressure or return stroke of the piston, and also in mantaining the heat in the walls of the high pressure cylinder, which, if cooled,

would rob the high pressure of its power in the form of heat.

Having thus described my invention what I claim is- An engine of the kind described comprising high and low pressure cylinders, pistons therein, a piston rod common to both cylinders, a valve casing communicating with each of said cylinders, a semi-cylindrical hollow valve rotatably mounted in said casing, and an exhaust pipe, an end of the valve having constant communication with said exhaust, the said valve being pressed inwardly to form a longitudinal groove upon one side, the said valve controlling communication between the two cylinders bringing them into communication by means of the groove and between the low pressure cylinder and the exhaust pipe, the valve cutting off communication between the two cylinders during communication between the exhaust pipe and the low pressure cylinder.

HERBERT H. PILOHER.

lVitnesses RoBT. VANCE, W. T. WATSON. 

